Gartner and Hiatt Chapter 16, pp. 323-340; Klein and McKenzie pp301-310
Name components of functioning renal parenchyma versus passive collecting system.
Be able to describe the flow of blood through the kidneys from the renal artery back to
the renal vein via either a superficial or a juxtamedullary glomerulus.
Recognize the main divisions of the nephron with light microscopy and know their main
Name the components of the juxtaglomerular apparatus.
List the components of the glomerular filtration barrier.
Be able to identify the following components of the renal corpuscle with light
microscopy: parietal/visceral epithelium, mesangium, capillaries, urinary pole, vascular
pole, and Bowman's capsule.
Be able to identify the following components of the renal corpuscle by electron
epithelial, endothelial, and mesangial cells; mesangium; basement
Understand the zones of the kidney and the locations of various parts of the nephron
within those zones.
Cortex, medulla, nephron, transitional epithelium, ureter, Renal corpuscle,
glomerular filtration barrier and bladder.
The kidneys are located in the retroperitoneal space with the upper
pole at the level of T12 and the lower at L3.
Fetal Features - In fetal life, the kidneys are composed of 7-18 pyramid-shaped
lobes (bases externally oriented, apices pointing inward) giving them a lumpy external
appearance. The demarcation between the lobes is obscured in time, so that the kidney
ultimately has a smooth appearance. It is important to be aware of the early lobar composition
of the kidneys to understand the internal architecture and nomenclature.
Adult Features -Each kidney weighs 120 to 170 gm and is 11-12 cm in length.
This occupies the outermost rim of tissue grossly, being about 1 cm in thickness.
Large vessels can be seen and delineate the cortex from the next zone inward, the medulla.
This zone is medial to the cortex and contains 7-18 conical masses called renal
. The base of each pyramid is at the corticomedullary boundary, while the apex of
each extends inward to the renal pelvis, forming a nipple-like protrusion called a
Sometimes several pyramids terminate in a common papilla, so that there are fewer papillae
than there are pyramids. Urine is released from small holes in the papillae into a passive
collecting system. Extensions of the cortex between adjacent pyramids are called
columns (of Bertin)
. Each pyramid and the surrounding cortical tissue in the renal column
, the total number corresponding to the number of lobes in the fetal kidney.